"Remember the Alamo!"
Tensions arose between American settlers and Mexicans as the United States continued to expand its borders. The Mexican-Amercian War, fought during 1846-1848, was over the control of the California and New Mexico territories. One of the most famous battles of this war was the Battle of the Alamo, in which Sam Houston led American troops in a victory over Mexican military forces. The war was resolved with the Treaty of Guadalupe Hildago and settled the border of the U.S. at the Rio Grande River and the western Pacific coast. This opened up nearly half a million square miles for continued slavery disputes.